Detachable lifting jack for fluid actuated tools



Dec. 23, 1952 E. A, LONGENECKER DETACHABLE LIFTING JACK FOR FLUID ACTUATED TOOLS Filed 001?. 30, 1948 2 SHEETS-SHEET l INVENTOR. ERNST A. LONGENECKER FIG. I

ATTORNEY Dec- 2 1952 E. A. LONGENECKER 2,622,562

DETACHABLE LIFTING JACK FOR FLUID ACTUATED TOOLS Filed Oct. 30, 1948 2 SHEETS-SHEET 2 IO I 72 l I 64 Q m 63 I I v INVENTOR.

W ERNST A. 'LONGENECKER BY i- 47 Fl 5 ATTORNEY Patented Dec. 23, 1952 DETACHABLE LIFTING JACK FOR FLUID ACTUATED TOOLS Ernst A. Longenecker, Wauwatosa, Wis., assignor to Le Roi Company, Milwaukee, Wis., a corporation of Wisconsin Application October 30, 1948, Serial No. 57,569

2 Claims.

This invention pertains broadly to percussive tools, but more particularly to fluid actuated tools of the percussive type such as paving breakers.

The operation of portable fluid actuated tools such as paving breakers, sinkers and the like, requires that the tool be manually held while the tool bit is performing the work. During this operation, the tool bit often becomes embedded in the material being cut to such an extent as rendering its removal very difficult. Heretofore the removal of a stuck tool bit was effected by the operator pulling and jerking the paving breaker and, through the tool retainer with which such machines are equipped, endeavoring to dislodge the tool bit from the material being out. This operation in addition to being tiresome, was also slow and inefficient, and often resulted in excessive wear or breakage of the paving breaker parts such as the tool retainer.

It is therefore one object of this invention to produce a paving breaker, or any other portable fluid actuated machine of the percussive type, with means capable of lifting or at least assisting in the lifting of the machine and its component tool bit from the material being cut.

Another object of this invention is to provide such fluid actuated tools with a lifting jack of simple and efficient construction, the operation of which can readily be controlled by the operator.

Another object of this invention is to provide such fluid actuated paving breakers with a fluid actuated lifting jack arranged and disposed in a manner enabling it to be actuated from the same source of motive fluid as the paving breaker without necessitating the use of additional motive fluid conveying conduits.

Other objects and advantages more or less ancillary to the foregoing and the manner in which all the various objects are attained will appear in the following description, which considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

In the drawing:

Figure l is a longitudinal sectional view of a paving breaker embodying the invention.

Figure 2 is a rear elevational view of the tool shown in Figure 1.

Figure 3 is a front elevational view of the tool shown in Figure 1.

Figure 4 is a fragmental longitudinal sectional view taken substantially through line 4-4 in Figure 2, showing details of construction.

Figure 5 is an enlarged sectional View of the upper end of the jack as shown in Figure 1.

Figures 6 and 7 are longitudinal views, partly in section, of the paving breaker assembly shown in different positions.

Referring to the drawings in which like symbols designate corresponding parts throughout the several views, [0 represents a housing formed with a cylindrical piston chamber [2, in which is reciprocably mounted a piston l4. As seen in Figure l, the upper end of the housing 0, hereinafter referred to as the rear or back end, is accurately machined to receive a valve block l6 having closely fitted therein a valve cap [8 and an automatic valve 20.

Covering the rear end of the housing It, there is a back head 2| provided with two hand grips 22 and 23, the hand grip 22 having extended over it a throttle valve actuating lever 24, through which a throttle valve, not shown, can be opened or closed for controlling admission of the motive fluid to the automatic valve 20.

As seen in Figure l, the lower end of the housing 10, hereinafter referred to as the front end, is covered by a bushing 25 which extends somewhat into the piston chamber [2 and forms the front end thereof. This bushing has a tappet 26 slidable therein and extending partway into the piston chamber l2 to receive the impacts of the piston 14. The bushin 25 also extends partway into a front or chuck housing 27, which together with the spacer 25, housing l0 and back head 2| are clamped together by through bolts 28 and 29.

Internally, the chuck housing 21 is accurately machined to receive a chuck sleeve 30 preferably pressed in or otherwise secured to the chuck housing 2'! against rotation relative thereto. Internally, the chuck sleeve is of hexagonal crosssection and is adapted to slidably receive the hexagonal shank 3| of a cutting tool 32. The free end of the shank 3| extends into the bushing 25 where it abuts against the tappet 26, while the other end of the shank is provided with a collar 33. Carried by the front end of the chuck housing 21, there is the usual tool retainer generally shown at 34, which retainer may be swung out of the path of the collar 33 to enable removal of the cutting tool from the chuck housing or may be swung in that path for engagement with the collar 33. In this last or operative position of the tool retainer, the cutting tool may be removed from the work by the operator, heretofore manually lifting the entire paving breaker and cutting tool from the work.

Since the paving breaker above described is one of the usual type, no further description is thought necessary other than pointing out that the housing [9, below the hand grip 22, is formed with a threaded orifice 35 having a bushing 36 screwed therein and adapted to receive the motive fluid connection about to be described. From the orifice 35, there is a port 31 leading therefrom to the throttle valve, not shown, operable by the lever 24.

Referring now more particularly to the invention, 38 represents the head housing of a fluid actuated jack, which housing is rigidly secured to the paving breaker by an apertured lug 39 clamped between the back head 2| and the nut of the through bolt 29. Internally, the housing 38 is accurately machined to receive the upper end of a tube 40, which is rigidly secured therein preferably by a weld 4|. The tube 49 extends downwardly from the housing 38 alongside of the through bolt 29 and in parallel with the center axis of the paving breaker. Toward its front end, it is rigidly secured to the paving breaker by a bracket 42 which is clamped between the head of the through bolt 29 and the chuck housing 21. Pressed or otherwise rigidly secured in the front end of the tube 40, there is a bushing 43 which acts as a sliding bearing for a piston tube 44 which is slidably mounted in the tube 49 and extends beyond its front end where it is terminated by a ground engaging point 45. The upper end of the piston tube 44 is equipped with a piston head assembly which includes a stem 46 having a shank -41 closely fitted within the upper end of the tube 44 and rigidly secured therein preferably by a weld 48. At its lower end, the stem 46 is also formed with an annular flange49 of a diameter substantially equal to the inner diameter of the tube 40. On this flange rests a cup-shaped packing 50 held in place by a relatively long spacer mounted on the stem 46, which has another cup-shaped packing 52 mounted on its upper end and held in position by a relatively short sleeve 53 mounted on the upper end of the stem 46. The upper end of the stem 46 is internally threaded to receive the threaded shank 54 of a retainer head 55, through which the sleeve 53 and spacer 5| are clamped on the flange 49. Mounted on the retainer head 55 between the sleeve '53 and on annular shoulder 56 formed on the head, there is a spring split ring 51"of a normal external diameter somewhat larger than that of a counterbore 59 provided within the housing 38. In the completely ret'racted position of the piston tube 44 within the tube 49, the split ring 51 frictionally engages the 'wall of the counterbore 58 to hold the piston tube in its retracted position.

Above the counterbore 53, the housing 38 is internally machined to receive a self-contained throttle valve assembly which includes a threaded bushing 59 screwed therein and having a cylindrical bore 60 extending therethrough, which bore has its upper end reduced as at 6i end to form 'a valve seat 62, while its lower end is threaded to receive a cap 63. Slidably mounted in the bore 60, there is a valve 64 constantly urged in fluid tight engagement with the valve seat 62 by a compression spring 65 located between the valve and the cap 63. This valve may 'be moved awayfrom its seat 62 by a slidable pin '66 having one end mounted in the valve while the other end protrudes from the housing 38, where it is engaged by a lever 61 pivotally secured to the housing 38 by a bolt 68. From the bolt 68, the lever extends under the handle grip 23 where it can readily be grasped by the operator for opening or closing the valve 64. Leading from the upper end of the tube above the piston assembly, there is an exhaust port 69 which may be closed by the valve actuating pin 66 or opened by an annular recess Ill provided thereon. The upper end of the bushing 59 is surrounded by an annular chamber H from which leads radial ports 12 extending through the bushing 59 and normally closed by the valve 64. Above the valve seat 62, there is also provided a small annular chamber 13 which is in constant communication with the upper end of the tube 49 above the piston assembly through a port 14.

Screwed in the bushing 35 located in the paving breaker housing It! below the hand grip 22, there is one end of a pipe nipple 15, while the other end has secured thereto by a coupling 16, the end of a fluid conveying flexible conduit 11. Intermediate its ends, the pipe nipple 16 is provided with a threaded hole 18 adapted to receive a gland nut 19 which forms one end of a small tubular conduit Bil, the other end of which is secured by a gland nut 8| to the tube housing 38 and opens into the inlet chamber ll through a port 82.

During operation of the machine, motive fluid from the flexible conduit 7"! is admitted to the paving breaker through the pipe nipple 76, bushing 36 and port 31, which port leads to the throttle valve, not shown, operable by the lever 24. From the pipe nipple 1-5, motive fluid is also admittedinto the inlet chamber H of the jack housing 38 through the port 13, conduit 89 and port 82. During normal operation of the machine, the operator holding on the handle grips 22 and 23 will maintain the machine assembly in a substantially vertical position with the cutting tool 32 applied to the work as shown in Figure 6. In this normal position of the machine, the piston tube 44 of the lifting jack is held in retracted position by the frictional engagement of the spring split ring 5'1 with the wall of the counterbore 58. In its retracted position, the pointed end of the jack is at about the same level as the end of the front housing 21, thereby preventing accidental engagement of the jack with the ground when the tool 32 is contacting the ground.

When the operator presses on the lever 24, motive fluid from the port 31 is admitted to the automatic valve 20 and therefrom, through a system of ports and passages, not shown, alternatively to the ends of the piston chamber 12 for effecting reciprocation of the piston l4. At the end of each forward stroke, the piston l4 delivers a powerful impact to the tappet 26, which is transmitted to the shank 3i and cutting tool 32 for performing the work.

When it is desired to remove the cutting tool 32 from the work, instead of manually lifting the paving breaker and cutting tool, the latter being lifted with the former due to the engagement of the tool retainer 34 with the tool collar 33, the operator simply squeezes the lever-67, located under the handle grip 23, toward the handle grip. In this instance, the end of the lever resting on the pin 66 will cause movement of the latter and valve l against the compression spring and movement of the valve away from thevalve seat 62. In this position of the valve pin 66, the exhaust port 69, previously cpenedby the pin recess i9, is now closed by the pin, and with the valve 64 opened, the motive fluid admitted into the inlet chamber 1| through the conduit 80, will flow into the upper end of the jack or tube 40 via the chamber 13 and port 14 to act on the piston assembly for driving the piston tube at outwardly. During this outward movement, the pointed end 45 of the piston tube will move into engagement with the surface of the material, hereinafter referred to as ground, being cut by the cutting tool 32. Since the ground being cut by the tool 32 is generally very hard, the pointed end 45 will be prevented from penetrating into such ground, thereby causing the motive fluid admitted into the upper end of the tube 60 above the piston tube head, to lift the paving breaker and tool 32 from the ground without any manual efforts of the operator.

In many instances, when the paving breaker and tool have thus been lifted from the ground, and when still supported by the jack, the paving breaker may simply be pivoted on the pointed end 45 for placing the cutting tool 32 in the desired position for the next successive cutting op eration. In such instances, when the cutting tool has been pivoted to the desired position, the operator simply releases the lever 51, thereby allowing the compression spring 65 to again close the valve 64 and prevent further admission of mo-- tive fluid into the upper end of the tube 40. With the valve M shifted into engagement with the valve seat 62, the valve pin recess ii! is again located to open the exhaust port 69, causing the motive fluid previously admitted into the upper end of the tube M! to exhaust through the port 69, thereby enabling retraction or inward movement of the piston tube 44. This inward movement will be partly effected by the weight, of the paving breaker until the cuttin tool 32 engages the ground, thereafter the pointed end t5 of the piston tube may simply be allowed to rest on the ground, or if preferred, may manually be pushed in the tube Ail and locked in retracted position by the spring split ring 51 frictionally engaging the wall of the counterbore 58.

In some instances when the cutting tool becomes badly lodged or stuck in the ground, it may be necessary for the operator, while holding the lever 6'! in jack operating position, to manually assist in lifting the paving breaker and tool from the ground. In such extreme instances it has been found that stuck tools heretofore almost impossible to remove, can readily be lifted from the ground with the jack assisted by the operator.

From the foregoing description, it will be understood that while this lifting device is shown and described in connection with a paving breaker, it can be used with any rock drilling or other portable tools. It will also be understood that the lifting device or jack forms a single unit; which, through the bolt 29, can readily be secured to or removed from the portable machine such as a paving breaker. Obviously when it is removed from the paving breaker, the threaded hole 13 in the nipple 16 will have to be closed by a solid plug or the like. Since the throttle valve lever 61 is carried by the jack, the removal of the jack will not affect subsequent normal operation of the paving breaker. It will also be understood that although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, the specific terminology is not intended to be restrictive or confining and that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. The combination of a fluid actuated portable machine having a cutting tool extending from one end thereof, a handle on the other end including two hand grips adapted to be grasped by the operator; means for admitting motive fluid to said machine including a throttle valve having an operating lever adjacent one of said hand grips, with a fluid actuated lifting jack forming a single unit including two telescoping elements, one rigidly secured to the machine for transmitting lifting forces thereto and the other adapted to engage the surface of the material to be cut by said cutting tool, means for admitting motive fluid to said jack including a throttle valve having an operating lever adjacent the other of said hand grips, and means detachably securing said one telescoping element to said machine, thereby enabling removal of the jack and its throttle valve as a unit and subsequent normal operation of the machine.

2. In combination, a fluid actuated portable tool, a fluid actuated lifting jack operatively secured to said tool alongside thereof, said jack forming a single unit including a throttle valve for controlling supply of motive fluid thereto, a throttle valve operating lever carried by said jack, a throttle valve and operating lever for said tool, both of said levers arranged and disposed in a manner enabling them to be manually actuated by the operator when normally holding the tool to the work, and means detach-ably securing said jack to said tool, thereby enabling removal of said jack as a single unit and subsequent normal operation of said tool.

ERNST A. LONGENECKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 23,104 Price Apr. 26, 1949 1,632,400 Gilman June 14, 1927 2.212329 Smith Aug. 20. 1940 

